How to combat the spread of the Asian Tiger and Rock Pool mosquitoes.
There are two pests spreading across the United States this summer. The Asian tiger mosquito, named for its distinctive black-and-white striped body, is a relatively new species to the U.S. Experts say that this mosquito is more vicious, harder to kill and, unlike most native mosquitoes, bites during the daytime. It also prefers large cities rather than rural areas. Entomologists have nicknamed this insect "the urban mosquito."
Asian Tiger Mosquito
Another reason it is called 'tiger' is because it is very aggressive. The bite of the Asian tiger mosquito is not particularly irritating to most people, but they are persistent biters.
These mosquitoes lay their eggs in water-filled natural and artificial containers like cavities in trees and old tires; they do not lay their eggs in ditches or marshes. The Asian tiger mosquito usually does not fly more than about 1/2 mile from its breeding site. Asian tiger mosquitoes are attracted to dark clothing, perspiration, carbon dioxide and certain other odors. The mosquito will bite squirrels, dogs, deer and other animals as well as people.
The Asian tiger mosquito was introduced into the United States in tire casings imported from Asia. Distribution of has spread the species to more than 20 states since 1985. The tiger mosquito is an important disease carrier in Asia. In the United States, it has been found to be infected with LaCrosse encephalitis viruses and West Nile virus, which can cause encephalitis (inflammation of the brain). However, it is presently unclear whether the Asian tiger mosquito will be a significant carrier of disease in the in the United States.
Another species imported from Asia is the rock pool mosquito (Aedes japonicus), which also came to the U.S. through the tire trade. This species is blackish-brown, with white scales on the lower part of its thorax and legs. It was first detected on Long Island, N.Y., and in areas of New Jersey in 1997. Even though it is not as vicious a biter as the Asian tiger mosquito, it is a big pest.
Rock Pool Mosquito
The Asian tiger was responsible for transmitting more than 200 cases of dengue fever, a sometimes-fatal viral infection, in Hawaii in 2001-02. A similar virus called chikungunya was transmitted in France and Italy, but no cases have been cited in the U.S. from the Asian tiger. Likewise, the rock pool mosquito is capable of transmitting the West Nile virus, but no cases have been traced to the species in the U.S.
Use insect repellents containing DEET, such as Deep Woods Off!, and products containing Picaridin, such as Cutter Skinsations.
Oil of lemon eucalyptus is a natural repellent.
Traps and Prevention
For the Asian tiger, use a mosquito trap that emits carbon dioxide which is produced by burning propane. You will also want to add a lure that contains lactic acid to attract daytime mosquitoes. Lures with octenol attract other mosquito species.
• Minimize time spent outdoors between dusk and dawn when mosquitoes are most active.
• Be sure door and window screens fit tightly and are in good repair.
• Wear shoes, socks, long pants and a long-sleeved shirt when outdoors for long periods of time, and when mosquitoes are most active. Clothing should be light colored and made of tightly woven materials to keep mosquitoes away from the skin.
• Use mosquito netting when sleeping outdoors or in an unscreened structure, and to protect infants when outdoors.
• When it is necessary to be outdoors, apply insect repellent as indicated on the product’s label. The more DEET a product contains, the longer the repellent can protect against bites. However, concentrations higher than 50 percent do not increase the length of protection. For most situations, 10 percent to 25 percent DEET is adequate. Apply to clothes when possible, and sparingly to exposed skin if the label permits. Consult a physician before using repellents on young children.
• Insect light traps do little to reduce the number of biting mosquitoes in an area.
• Spraying your backyard with an insecticidal fog or mist is effective only for a short time. Mosquitoes will return when the spray dissipates.
• Installing bird or bat houses has been suggested as a method of mosquito control. However, there is little scientific evidence that these insect-eating animals significantly reduce mosquito populations around homes.
• Remove any water-filled containers like old tires, food containers and buckets from your yard.
• Keep mosquitoes from breeding in bird baths, pet water dishes and plastic wading pools by emptying them at least once a week.
• Roof gutters should be kept clean of fallen leaves and other debris so that water does not collect in them.
• Neighborhood residents should work together to eliminate breeding sites in open spaces and vacant lots.
• Report piles of discarded tires or other accumulations of water-holding junk to local health officials.
Some ways to ease the pain of mosquito bites is by treating the bites with heat or cold to confuse the brain.
• Ice. An ice pack decreases inflammation and reduces itching.
• Anti-itch lotions. Creams containing 1% hydrocortisone reduce inflammation. Products that contain camphor and menthol, such as Sarna, also help. To boost the effect, store the lotions in the refrigerator. Note: Calamine lotion dries out the affected area and therefore is not recommended.
• Benadryl. It stops the release of histamine, which triggers inflammation.
• Therapik. This device, approved by the Food and Drug Administration (FDA), delivers heat to the affected area to reduce itching and inflammation.
• Toothpaste. Helps if it contains menthol.
Other unproven remedies include the following:
• Paste of baking soda and water
• Apple-cider vinegar
• Lemon juice
• Cigarette smoke
• Fabric-softener dryer sheets
Since urban areas tend to be warmer than rural areas by 5 to 10 degrees, cities have seen tiger mosquitoes earlier and surviving longer, often into October. Eggs of Asian tiger and rock pool mosquitoes are also able to "overwinter," meaning they can survive a cold, dry climate. To hatch the following year all they need is exposure to water in warmer temperatures.
These urban mosquitoes are what entomologists call "container mosquitoes." Instead of marshes and natural bodies of water, both Asian tiger and rock pool mosquitoes can breed in small, artificial containers, such as tires, toys, cans and concrete structures. A rule of thumb for container mosquitoes is “Water plus seven days equals mosquitoes."
Cities are finding it difficult to control these mosquitoes with traditional spraying due to the fact that their breeding locations are widely distributed and difficult to reach.